Heat exchanger



3725, 1946? v A. J. FAusEK ETAL A. I 2,402,881

HEAT XGHANGER Filed Jan. 2, 1943 v 2 sheets-sheet i.

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l Patented June `25, 1946 HEAT EXCHAN GER Arthur J. Fausekv and rwng F.Fausek,

. Clayton, Mo.

A pplicatonJanuary2,1343, Serial No. 471,130

This invention relates. generally to heat exchangers and more specicallyto heat exchangers of the type comprising a multiplicity of tubesarrangedwithin a housing, through which tubes and housing'fluid, gas, orother medium, whose temperature is to be changed, passes, Ithepredominant object of the invention being to provide a heat exchanger ofthe type mentioned,

which includes tubes of such form and arrange-- ment that a maximum ofheat exchangeis obtained in a housing of relatively small diameter andreduced height and which tubes may be conveniently removed for repair orreplacement.

Prior to this invention heat exchangers of the y general type to whichthe structure of the present -A invention relates were deficient in twomajor re spects, these points of deficiency being, first, that when thetubes were long and straight the heat exchanger was necessarily of `verygreat height or length, in order to obtain the desired heat exchange,and, secondly, that when other than straight tubes were employed, orwhen an excessive number of shorter straight tubeswere used, the heightor length of the heat exchanger was reduced but the task of removingtubes for repair or replacement was rendered most difficult.

` The prime purpose of this invention, therefore, .is to provide a heatexchanger whichv is of such unique construction and arrangement that thestructure is of vminimum height and the tubes thereof may beconveniently removed for repair or replacement, such result being aconsequence of the form of the tubes and their arrangement within thehousing of the heat exchanger.

Fig. 1 is a side elevation of thevimproved heat exchanger, conductorsleading to and from the heat exchanger being broken away.

Fig. 2 is an enlarged vertical section taken through the heat'exchangershown inFig. 1. por'- tions of the structure being broken away inorderlto permit of the view being drawn to a larger sca e.

6 claims. l(o1. 257-220) tubes .after its nal shape has been impartedthereto.

The improved heat exchanger disclosed herein may be employed for thepurposeof changing temperatures of various mediums which are capable offlowing, and in order to disclose one embodiment of the invention forpurposes of illustration, merely, we illustrate in the drawings a heatexchanger of the improved construction and arrangement which is adaptedparticularly for use in increasing the temperatures of nitrogen andoxygen. Thel limproved heat exchanger isl designated generally in thedrawings bythe reference character A and it. comprises an outer housingI which includes, a top member 2, a bottom member 3, and a shell i oftubular or other suitable shape. The top member 2 and the bottom member3 are secured to top and bottom portions of the shell li in any suitablemanner to provide'fluid and gas-tight joints -at the points ofconnection between said top and bottom mem'- bers and the shell, thebottom member 3 being provided with a boss 5 provided with ascrewthreaded opening which communicates with the interior of thehousingand receives a nitrogen inlet conductor 6, and the top member 2being 4 provided with a boss 'I provided with a screwthreaded openingthat communicates with the interior of the housing/and receives anitrogen outlet conductor 8.

Arranged within the upper portion of the housing I is a manifold 9 forhigh pressurel air, said manifold having a portion extended through anopening formed through the wallof the shell d to provide an exteriorinlet conductor it which conducts high pressure air to the manifold 9.

f Aiso,` arranged in the lower portion of the housing I is a similarmanifold II for'high. pressure air which likewise includes a portionthat eX- tends through an opening formed through the Y wall of the shellS, this portion providing an ex- Fig. 3 nis' a horizontal section takenapproxi- I mately on line 3 3 of Fig. 2. y

Fig. i is a plan view of a section'of one of the baiiies forming a partof the heat exchanger i1- 'lustrated in Figs. 1 and 2.

Fig. 5 is a plan view of a section of another of the baies of theimproved heat exchanger.

Fig. 6 is an elevation on a reduced scale of one of the tubes of theheat exchanger illustrating the form thereof before nal shaping of saidtube.

Fig. is a sectional-plan view of the tube lilterior outlet conductor I2which conducts high pressure air from. the manifold Il. Preferably,though not necessarily, the portions of the manifolds 9 4and II whichare located within the housing I are of circular formation with theinlet-and outlet conductors III and l2 leadingto the circular portionsof the respective manifolds. Also, the `ioints between'the surfaces ofthe inlet and outlet conductors I0 and I2 and the walls of the openingsthrough which said conductors pass. are

suitably sealed to render said joints uid and N gaa-tight. g l

.Extended between the manifold Sand the many Fig. 8 is a sectional-planview 'of one of the w ifold il is a plurality of-high pressure air pipesi3- a 3 each of which is connected into the manifold 9 at its upper endand is similarly connected into the manifold I I at its lower end. Themanifolds 9 and I I are provided with outwardly extended, hollow bossesI4 which communicate with the interiors of the manifolds and receiveopposite en d portions of the pipes I3, said end portions of the pipesbeing soldered or otherwise secured to the bosses to provide iluid andgas-tight contact therebetween; Each of the pipes I3 has a tortuousformation, being made .up of a multiplicity of return bends andconnecting portions between said return bends, as shown in Fig. 6, whicheX- tend continuously throughout substantially the entire length of thepipe. Also, the undulant portion of each pipe, made up of the returnbends and the connecting portions therebetween, is curved transversely,as shown in Fig. 3, so as to provide for the close nesting of amultiplicity of said pipes in the relativelysmall space provided withinthe housing I.

The importance of the transverse curvature of the pipes I3 which permitsof said pipes being nested within the housing I, as shown in Fig. 3,will be realized if it be considered how very much larger in diameterthe housing would have to b'e if an equal number of uncurved pipes werearranged radially within a housing.' Also, in such anI imaginedarrangement much space within the housing would be unoccupied by pipes,and much of the medium passed through the housing furthe purpose-ofchanging the temperature thereof wouldnot come into close contact withthe pipes, with the result that the heat exchanging operation 'would notbe efficiently performed. In the structure of the present invention,however, the pipes I3, because of the-curvature thereof and theconsequent closely nested condition of said pipes within the housing,substantially iill the entire space within the housing I so that medi1nnpassing through the housing exteriorly of the pipes I3 for the purposeof changing the temperature thereof, must necessarily move in closecontact with said pipes I3, with the consequence that the heatexchanging operation is very effectively performed.

Another important feature of the present invention is that in spite ofthe closely nested condition of thepipes I3 any one of said pipes may beconveniently removed for repair or replacement. Such removal of a pipemay be accomplished by disconnecting the opposite end portions of thepipe from the manifolds 9 and I I and then rotating the pipe to beremoved laterally to move same in a curved path, out of its positionv inthe nest of pipes. In this connection it is Ypointed out that the shellI is' made up ofa pair of semicircular sections which are soldered' orotherwise secured together at opposed butt joints 4' which extendlongitudinally of the shell from end to end, as shown in Fig. 3. Becauseof this arrangement the paired sections of the shell may be disconnectedat the joints 4' and separated after the top, and bottom members 2 and 3have been removed, to give free access to lthe nested pipes I3.

Arranged in the upper portion of the housing I, immediately below themanifold 9, is an oxygen manifold I5, and arranged in the lower portionof the housing I, immediately above the manifoldv II is a similar oxygenmanifold I6. The manifoldsV I and I6 correspond in construction to themanifolds 9 and II in that the porfold I6 includes a portion whichextends through an opening formed through the Wall of the shell 4 toproiu'de an oxygen inlet conductor I1, while the manifold I5 includes asimilar part extended through an opening formed through the Wall of theshell 4 which provides an oxygen outlet conductor I8, the contactingpoints of the surfaces of the inlet and outlet oxygen conductors and thewalls of the openings being suitably sealed. The oxygen manifolds I5 andI6 have formed thereon outstanding, hollow bosses I3 which commuhicatewith the interiors of said manifolds.

Arranged within the housing I of the heat exchanger A is a plurality ofoxygen pipes 20 which extendbetween, and are connected, at theiropposite ends, into the manifolds I5 and I6, each oxygen pipe 20 havingits opposite .end portions received by corresponding bosses I9 of themanifolds I5 and I6 and said end portions of the oxygen pipe beingsecured by solder, or otherwise, to said bosses so as to provide uid andgas-tight contact therebetween. As in the case of the high pressure airpipes I3 each of the oxygen4 pipes 20 has a tortuous formation, beingmade up of a plurality of return bends and connecting por- .tionsbetween said return bends which extend continuously throughoutsubstantially the entire length of the oxygen pipe. Also, as in the casecorresponding portions of the high pressure air pipes, and because thehigh pressure air pipes are of heavier wall thickness to hold the highpressure air. As shown in Fig. 3, the oxygen pipes 20 are nested withrespect to the high'pressure air pipes I3 within the housing I, eachoxygen pipe being arranged in curved alinement relative to one of thehigh pressure air pipes.

Arranged within the housing I and suitably supported therein, is aplurality of baffles 2l and 22. The bailles 2l and 22 are disposedwithin lthe housing I in staggered relation so as to cause nitrogenpassing upwardly through the housing to follow a. tortuouscourse,thereby preventing l short-circuiting of said nitrogen through thehousing, and causing it to move in contact with a maximum number ofportions of the high pressure air pipes I3. Each of the ballles 2l and22 is made upof a pair of semic'ircular sections. as shown in Figs. 4and 5, these sections being arranged in abutting relation at theirspaced straight, inner edges 2l' and 22' to provide the complete baille.Also, each baille section includes an inner edge 23 or 24 between thespaced straight, inner edges 2l or 22', which is curved to correspondwith thecurvature of the outer edge 25 or 26 of the baille section. Thearrangement of the bales within the housing is such that the innercurved edges 23 of the bales 2| are spaced a substantial distance inanoutward direction from the axis of the housing-I, while the outercurved edges of the baffles 22 are spaced inwardly a considerabledistance from the inner .face of the wall of the shell l of the housingI.

Because of this arrangement the nitrogen passing upwardly through thehousing will follow a tortuous path, as Amentioned above, the body ofnitrogen flowing around the outer edges 26 of the baffles 22 and aroundthe inner edges 2 5 of the baliies 2| as indicated by the arrows in Fig.2.

Additionally the inner, curved edges 24 of the baffles 22 and the outercurved edges 25 of the bailles 2| are provided with notches 21, portionsof the high pressure air pipes through the notches of the bailles 22 andportions of the oxygen pipes extending through the notches of thebaffles 2 I.

By referring to Figs. 2 and 3 it will be noted.

that the arrangement of the innerportions of the high pressure' airpipes I3 is such that a well is provided vertically and centrally withinthe bank of high pressure air pipes, and in order to block oi this wellso that nitrogen may not short-circuit therethrough, an elongated bag28, formed of canvas or other suitable material, which is filled withrockwool or other suitable insulating materiaLis disposed in said bag.The bag 28 is formed of a flexible material, suchA as canvas, so that itmay adjust itself to the inner portions of the high pressure air pipesand thus effectively seal off the well in which it is arranged. The bagmay be supported in any suitable manner, or the contact thereof with thehigh pressure air pipes may be relied onfor the support of said bag.

From the foregoing, and from the drawingsforming a -part of thisspecification, it is thought that the operation of the improved heatexchanger will be obvious, the nitrogen entering the apparatus by way ofthe inlet conductor 6 and passing tortuously4 in an upward directionthrough thehousing, in contact with the high pressure air pipes I3, fordischarge from theapparatu's by Way of the outlet conductor 8. Also, theoxygen passes into the apparatus by way of the inlet conductor I'I andpasses upwardly through the pipes 20 for discharge from the apparatus byway of the outlet conductor IB. While the high pressure air passes intothe apparatus by way of the inlet conductor I Il and passes downwardlythrough the pipes .I3 for discharge I3 extending from the apparatus byWay of the outlet conductor` I2. In the operation of the particularapparatus illustrated in the drawings the high pressure air will enterthe apparatus at room temperature and leave theapparatus at from 120 C.to 185 C., while the nitrogen and the 'oxygen will enter the apparatusat from '-1859 C. to 170 C. and will leave the apparatus at roomtemperature. These temperature figures are approximate as duringexistence of different conditions there may be some variance inconnection with the incoming and outgoing temperatures of the mediumspassing through the apparatus.

The length and form of pipes provide a maximum of heat exchange in assmall a diameter and as short a height as possible, thereby conservingon material and weight. Additionally, the lengths of the'pipes in the4various units make possible graduated temperature zones without beinginfluenced unduly by metal mass, and the undulant form of the individualpipes allows for free expansion and contraction of said pipes, thuseliminating any tendency that expansion and contraction of the pipeswould pull the ends of the pipes loose from the manifolds at theirpoints of attachment thereto. Also, instead of removing a pipe to berepaired or replaced from the nest of pipes by `rotating said pipelaterally out of the nest of pipes, as has been previously explainedherein, such a pipe may be removed from thetop or bottom of theapparatus.

It is pointed out that heat exchangers of the improved construction ofvarying capacities may be produced by merely employing Ihousings of dirlferent diameters so as to permit of the employment of high pressure airpipes of greater or less number. By` so increasing the capacity of theheat exchanger an apparatus of increased capacity may be providedWithout increasing the height of the apparatus.

We claim:

1. A heatexchanger comprising a housing having inlet and outlet Ameansfor passage of a medium into,` through, and out of -said housing, a pairof spaced apart manifolds disposed within said housing and providedrespectively with inlet and outlet means, a plurality of pipes arrangedwithin said housing and connected at their opposite ends into saidmanifolds for passage through the manifolds and pipes of a secondmedium, a second pair of spaced apart manifolds disposed within saidhousing and provided respectively with inlet and outlet means, and aplurality of pipes arranged within said housing and connected at theiropposite ends into said second pair of manifolds for passage through thesecond pair of manifolds and the pipes connected thereto of a thirdmedium, each of the pipes connected tothe first-mentioned pair ofmanifolds and each'of the pipes connected to the secondmentioned pair ofmanifolds being provided with return bends and .connecting portionsbetween said return bends which give to the pipe a tortuous formation inthe direction of the length of the pipe and said tortuous portion of thepipe being curved transversely of the pipe, said pipes connected to thefirst-mentioned manifolds and disposed within said housing and providedrespectivelyv with inlet and outlet means, and a plu; rality of pipesarranged within said housing and connected at their opposite ends intosaid second pair of manifolds for passage through the second pair ofmanifolds and the pipes connected thereto of a third medium, each of thepipes connected to the first-mentioned pair of manifolds and each 0f thepipes connected to the secondmentioned pair of manifolds being providedwith return bends and connecting portions'between said return bendswhich give to the pipe a tortuous formation in the direction of thelength of the pipe and said' tortuous portionof the pipe being curvedtransversely of the pipe, said pipes connected to the mst-mentionedmanifolds and *pair of spaced apart manifolds disposed within saidhousing and provided, respectively with inlet and outlet means, aplurality of pipes arranged within said housing and connected at theiropposite ends into said manifolds for passage through the manifolds andpipes of a second mereturn bends and connecting portions between saidreturn bends which give to the pipe a tortuous formation in thedirection of the length of the pipe and said tortuous portion of thepipe being curved transversely of the pipe, said pipes connected to thefirst-mentioned manifolds and said pipes connected to thesecond-mentioned manifolds being arranged within the housing in aclosely nested condition, and baille means within said' housing forcausing the first-mentioned medium to follow a tortuous path during itspassage through the housing.

4. A heat exchanger comprising a housing having inlet and outlet meansfor passage of a medium into, through, and out of said housing, a pail`of spaced apart manifolds disposed Within said housing and providedrespectively with inlet and outlet means, a plurality of pipes arrangedwithin said housing and connected at their opposite ends into '.saidmanifolds for passage through the manifolds and pipes of a secondmedium, a second pair of spaced apart manifolds disposed within saidhousing and provided respectively with inlet and outlet means, aplurality of pipes arranged within said housing and connected at theiropposite ends into said second pair of manifolds for passage through thesecond pair of manifolds and the pipes connected thereto of a thirdmedium, each of the pipes connected to th rst-mentioned pair ofmanifolds and each of the pipes connected to the secondmentioned pair ofmanifolds being provided with return bends and connecting portionsbetween said return bends which give to the pipe a tortuous formation inthe direction of the length of the pipe and said tortuous portion of thepipe being curved transversely of the pipe, said pipes connected to thefirst-mentioned manifolds and said pipes connected to thesecond-mentioned manifolds being arranged within the housing in acloselynested condition, the arrangement of the nested pipes within the housingbeing such that a well is formed centrally and longitudinally of thebank of pipes, and means for blocking said well.

5. A heat exchanger comprising a housing having inlet, and outlet meansfor passage of a medium into, through, and out of said housing. a pairof spaced apart manifolds disposed within said housing and providedrespectively with inlet and outlet means, a plurality of pipes arrangedwithin said housing and connected at their opposite ends into saidmanifolds for passage through the manifolds and pipes of a secondmedium, a second pair of spaced apart manifolds disposed within saidhousing and provided respectively with inlet and outlet means, aplurality of pipes arranged within said housing and connected at theiropposite ends into said second pair of manifolds for passage through thesecond pair of manifolds and the pipes connected thereto of a thirdmedium, each of the pipes connected to the first-mentioned pair ofmanifolds and each of the pipes connected to the second-mentioned pairof manifolds being provided with return bends and connecting portionsbetween said return bends which give to the pipe a tortuous formation inthe direction of the length of thepipe and said tortuous portion of thepipe being curved transversely of the pipe, said pipes connected to thefirst-mentioned manifolds and said pipes connected to thesecond-mentioned manifolds being arranged within the housing in aclosely nested condition, the arrangement of the nested pipes within thehousing being such that a well is formed centrally and longitudinally ofthe bank of pipes, means for blocking said Well, and baffle means withinthe housing for causing the first- `mentioned medium to follow atortuous path during its passage through the housing, A

6. A heat exchanger comprising a housing having an inlet and an outletfor passage of a medium into, through, and out of said housing, a groupof pipes arranged within said housing, inlet and outlet means into whichthe opposite ends of said group of pipes are connected for passagethrough said pipes of a second medium, a second group of pipes arrangedwithin said housing, inlet and outlet means into which the opposite endsof said second group of pipes are connected for passage through saidsecond group of pipes of a third medium, each pipe of thefirst-mentioned group of pipes and each pipe of the second-mentionedgroup of pipes being provided with continuously connected return bendswhich give to the pipe a tortuous formation in the direction of thelength of the pipe and the pipes of the first-mentioned group of pipesbeing curved transversely of the pipes,- the first-mentioned group ofpipes and the second-mentionedgroup of pipes being arranged within thehousing in closely nested rclation.

ARTHUR J.4 FAUSEK. IRWING F. FAUSEK.

